TruOil over tung oil finish?

[flabbydan]

I have a walnut stock that has only three or four coats of tung oil finish on it.  The grain isn't even close to being filled yet.  I was wondering if I could put Tru-Oil over the tung oil finish, or would I have to sand it down to bare wood first?  Thanks
Dan

[John Traveler1]

flabbydan,

I've done several rifle stocks just as you described: TruOil over a partial tung oil stock.  Also the reverse.  There doesn't seem to be any adverse effects to the final finish, such as separation, crazing, or spotting.  Of course, I don't know what the long-term effects are yet, it's only been a couple of years for these stocks used in a moderate-to-dry climate.  I would use steel wool or wet-n-dry sandpaper between coats to level the finish.

As I understand it, tung oil, TruOil, Linspeed, and boiled linseed oil finishes are mutually compatible, with the only real differences between them to be "driers" that speed up the curing of the finish.

I prefer tung oil because it is more water resistant than linseed oil.  TruOil is nice because it is so convenient to use, and makes a tough oil finish.

HTH
John

[gunnut69]

I agree with JohnT.  The finishes are not mutually exclusive..  Actually I use a product called 'okene' by Pratt&Lambert first to sort of assist the waterproofing.  This is a version of the Danish oil dinish and is very penetrating..  I then follow with TruOil.  My first tung oil experiments were in the '70s.  The finish is much more water resistamt than TruOil alone but not more so than a TruOil/wax finish..  The tungoil makes a beautiful stock but high temps can cause crazing or cracking.. As a test I baked a finished stock in the backseat of my Dad's '51 Chevy, black too..  It also was a bit harder and cracked under impact worse than TruOil.  A thinned coat of Tung oil forced into the wood and finished with TruOil may be the best yet..  I've not tried that..Oh well, another experiment..  Remember whatever material you use the last ccoats should be rubbed out with 0000 steel fur between coats.  It's almost an exercise in hand polishing.. I'm putting the finishing touches on a stock for a M700 Titanium.  The gentleman want to hunt with the synthetic and put the wood on for the case?  He certainly chose a pretty piece of wood..  My son got a digital camera and promised to show me how to upload the photoes!  I'll try and get them posted when the checkering is finished..  The guy asked that the checkering be kept simple, a point pattern perhaps?  I like that, it allows the wood's beauty to show thru..  The gun show we're staging is taking a lot of my time..but I promised the rifle soon!   Good luck with the finish!

[flabbydan]

Thanks for the help, guys!
Dan

[victorcharlie]

I just finished a stock for my Marlin 336C in .35 Remington.  I used 5 coats of boiled linseed oil applied every day, then 15 coats of Tru-oil over that.  I tried several different methods of application, hand rubbed first, then a small brush.  I found the best way to put the Tru-oil on is with an air brush.  Cut the Tru-oil 50/50 with mineral spirits.  The longer you can let it cure between coats the better.  It was hard not to spray every day, but the coats sprayed after 2 or 3 days of curing had fewer problems.....
 
I have read many articles on the subject, and although I have never tried it, tung oil should work well under Tru-oil, just like the boiled linseed oil did.
 
I will say, that I should have continued with more coats of linseed oil to more completely fill the grain before going to the Tru-oil.  I think if I had went a few more coats, then 15 coats of Tru-oil could have been cut down to about half that.  
 
The Tru-oil is much more "sticky" than linseed oil and starts to dry quicker when sanding to fill the grain.
 
There is no doubt in my mind that an airgun will give a much more even finish, and do it quicker with less time and effort  than when hand rubbed or applied with a brush.
 
One other thing......I'd only use steel wool on the finish coat as when I used it it left wool embedded in the stock....I didn't really notice it until I sprayed on the next coat and allowed it to dry.  I could see it under the finish.  This caused me to sand deeper to get rid of the wool.  I used 400 grit wet and dry sand paper between coats, then switched to 600 for the last 3 or 4 coats and finished off with 1500 grit.  I didn't sand the final coat and this produced a finish you can reach into.    
 
Lots of different ways to do this.......most will produce very good results but have patience, go slow and have fun!